Urea–Zinc Chloride Eutectic Mixture-Mediated One-Pot Synthesis of Imidazoles: Efficient and Ecofriendly Access to Trifenagrel

The low-melting mixture urea–ZnCl2 was evaluated as a novel reaction medium for the synthesis of imidazoles. The reaction between a dicarbonyl compound, ammonium acetate, and an aromatic aldehyde is efficiently catalyzed by the eutectic solvent, yielding a wide variety of triaryl-1H-imidazoles or 2-aryl-1H-phenanthro[9,10-d]imidazoles in good to excellent yields. In addition, the eutectic solvent was reused in five cycles without loss of its...